Training None Intent in LUIS

Question

I have a travel bot with following intents:-

1. BookAFlight (trained with 20 utterances)

2. GetTicketCopy (trained with 20 utterances)

3. CancelTicket (trained with 20 utterances)

4. None (default) (currently not trained)

MS documentation suggests that I train None for atleast 1-2 utterances for every 10 utterances added to other intents. Which means I would need say 6-12 utterances to train None.

My query is what kind of utterances should be used to train None?

1. Everything under the sun apart from what is relevant to my bot ( for e.g. I want to order a pizza, How is the weather today, Who is the president of USA? etc.)

2. All negative statements corresponding to the utterances used to train my other intents (for e.g. I don't want to book a flight ticket, I don't want to take a print out, I don't want to cancel my ticket etc.)

3. All utterances that corresponds to intents currently not covered in my scope but which users could still ask to a travel bot (for e.g. I want to Book a Cab to the airport, What is the status of my flight)

Long story short, I am trying to identify what kind of utterances should go into my None intent . Is None the right place to handle "Negative" variations of valid utterances.

Answer 1

None intent is not made for "Negative variations" but to tag everything that is not managed by your other intents.

So you should add utterances corresponding to cases that your bot cannot handle but linked to your context (your 3rd idea).

For example in one of my projects, None intent is trained with other use-cases of my customer than the one I will treat with my bot, based on my customer logs. And it's helping avoiding to throw an intent in a bad case

Answer 2

The LUIS docs suggest you should use COMPLETELY off-topic utterances for the None intent: "Start with something specific that your bot shouldn't answer such [as] 'What kind of dinosaur has blue teeth?'" They also suggest that for positive and negative reaction to some actions you create separate intents. Eg. Don't want a car / Want a car. Alternatively use single intent and mark relevant terms as positive and negative entities.